Thompson insists their statements jeopardise the SPL's commercial interests as the league bids to steer clubs through turbulent economic times exacerbated bythe demise of former broadcasting partner Setanta.

'If you're talking about the Old Firm leaving, where does it leave us with regards to contracts?

'We have got a five-year deal with ESPN and Sky with a three-year break.

'I assume if they went somewhere else, that contract would be null and void. It would have serious consequences on the game.'

SPL chief executive Neil Doncaster also branded Lawwell's comments 'unhelpful' as he focuses on bringing more income to the 12 clubs.

'I don't think the Old Firm, particularly Celtic, really care about
anyone else,' added Thompson, who challenged Lawwell to explain his
intentions at the next SPL meeting.

Controversial: Celtic's Peter Lawwell and Rangers' Martin Bain are in favour of their clubs breaking away from the SPL and joining a more lucrative league

'After the demise of Setanta they had a go at all the clubs for voting for the current deal. Now they are undermining the SPL again.

'I don't know what's trying to be achieved. Potential sponsors don't know where they're going to stand in two or three years.'

Much of the recent speculation surrounding the Old Firm's future has centred on plans for a English Premier League 2 that may be discussed at the next Premier League meeting.

But Bain sees a European league as a more likely scenario than an invite to the English ranks.

Spot on: Kenny Miller scores a penalty for Rangers in the recent Old Firm derby

'There are a number of like-minded clubs like Rangers and Celtic throughout Europe - big, big clubs playing in smaller leagues - who are hamstrung by their environment,' he said.

'I think, as that groundswell grows, UEFA will take note of it and that will maybe lead to other things.

'If the Premier League or a lower league want us and the arithmetics are right, and it's right for the club as a brand, then it's something we will explore.'

Lawwell had earlier admitted he was in 'awe' of the Barclays Premier League's 'fantastic product', while admitting an extension of the Champions League would be a 'natural' solution for Celtic to expand their income base.

But he also refused to rule out a move to the bottom level of the English leagues.

'We're in a watching brief,' Lawwell said. Fundamentally, we need someone to want us. We'll be waiting for someone to want this magnificent football club to comeand compete with them, and if that benefits Celtic and its supporters, then wewould be delighted to take part.'